I am using a Kensington TurboBall with one of the buttons programmed as Double-click. Sometimes when I use it to fly a card to the top, Dashboard closes as though I had clicked outside a Widget. It is possible that I may be moving the ball to the next card, but I am pretty sure I have seen it when my hand was not touching the ball. I rarely double-cick any other Widget, so I cannot say whether it may be a Dashboard issue or something in Mondo.